Maged is reading a book with 91 pages. He has read 21 pages. How many pages are left?
We know that Maged’s book has 91 pages and that he’s read 21 pages. So we need to take away 21 from 91, and we can use a place value chart to make this easy. First, we take away in the ones column. Here we have one take away one, which is zero. And we have nine tens, and we need to take away two, which is seven. 91 take away 21 is 70. Maged has 70 pages left in his book.